The rock boring machine drive head apparatus of the present invention has utility for use on rock boring equipment of types well-known in the rock boring field, such as the raise drill shown, for example, in Porter U.S. Pat. No. 3,754,605, Klein U.S. Pat. No. 3,797,587, West U.S. Pat. No. 3,800,887, and Porter U.S. Pat. No. 3,802,057. In such equipments, threaded drill sections are connected end for end to form the drill string and rotatably driven by the drive head while the drive head housing is hydraulically thrust downwardly, or upwardly as the case may be, to urge the drill into the ground being drilled. In such rock boring equipment, it is generally known and highly desirable to have a floating and swivelling bearing for the drive connection in order to absorb overturning forces transmitted by the drill string during drilling, and to guard against any unforeseen loads that might occur during the drilling operation. However, the provision of floating and swivelling bearings in the drive head is expensive, and when these parts become worn, replacement of the worn parts is also expensive and time consuming. The driving components utilized in connection with floating and swivelling bearings commonly include splined drive members, which normally wear in the recoiled position of the bearing, so that after extended use the remainder of the length of the splined teeth along the axial recoil slide path are usually in good condition while those at the recoiled end are worn.